The technology described below is the one discussed by the present inventors in studying and accomplishing the present invention, and is roughly as described below.
A memory-module is one of the module products mounting a plurality of semiconductor devices.
The memory-module includes a plurality of semiconductor devices having memory chips that are mounted on one surface or on both the front and back surfaces of a module board. In mounting the memory on a personal computer or a work station, the memory-module mounts the memory by being mounted on a mother board provided in the personal computer or the work station with each module as a unit.
As the semiconductor device mounted on the memory-module, there has been used the one of the surface mount type called SMD (surface mount device) having a semiconductor chip sealed with a resin and having lead terminals (external terminals) for drawing the electrodes to the outside of the resin-sealed portion, as represented by TSOP (thin small outline package) and TCP (tape carrier package).
Module products of various structures have been disclosed in, for example, Japanese Patent Laid-Open Nos. 209368/1998, 258466/1989 and 86492/1995.
Japanese Patent Laid-Open No. 209368/1998 discloses a CPU (central processing unit) module, and Japanese Patent Laid-Open No. 258466/1989 discloses a memory-module mounting SMD parts having a DRAM (dynamic random access memory) chip. Japanese Patent Laid-Open No. 86492/1995 discloses technology for applying an underfiller resin in the MCM (multi-chip module).